Good article in Popular Mechanics:
Link
Quote
Nick Cook, the former aviation editor for Jane's Defense Weekly, says there are a number of reasons why personnel might have boarded ships and seized electronic data. "It could mean it was sensitive information," he says. "It could mean this was an exercise."
Regarding the latter possibility—that this was a secret military test of some sort—Cook, a career defense journalist, says in his opinion it was unlikely this was a classified test. "It's not impossible, but I wouldn't think it's likely. It would be so against the norm of my experience with how the black world conducts testing."
Having spent a decade investigating the potential for secret highly advanced aerospace technology, and publishing these efforts in The Hunt for Zero Point, Cook was cautious in offering any definite conclusions as to what the Nimitz carrier group had encountered. Cook says it's possible, but not likely, that the "Tic Tac" was some type of classified drone.
"I searched for 10 years, and never found any compelling evidence that the type of technology exists," Cook says. "[That] doesn't mean it couldn't still exist … I just never found any smoking gun for it."
But when pushed, the career aviation journalist soberly says, "In the balance of probabilities, I don't think it's ‘ours'."